On Tuesday, the team’s first-round pick was sidelined again, unable to participate in practice because of a sore right hamstring, and coach Tom Coughlin ruled the rookie wide receiver out for Friday’s preseason game against the Jets at MetLife Stadium.

Beckham, who hasn’t participated in a full practice since straining his hamstring during the first day of training camp, had slowly made progress over the past few weeks, showing flashes of potential in individual sessions and joining 11-on-11 team drills, but he woke up Tuesday morning feeling soreness in his hamstring and didn’t want to risk aggravating it any further.

“We have progressively built up my workload,” Beckham told the Giants website. “I was sore [in the] morning, and I didn’t work [Tuesday] because we didn’t want a setback, and I don’t consider this a setback. I see it as another step in getting back to full strength.”

Beckham showcased a snippet of his blazing speed during Monday’s practice, catching a short crossing route, but after turning up the field, the 21-year-old pulled up and reached for his right hamstring. He appeared to have been hit in the hamstring, but told strength and conditioning coach Jerry Palmieri he was fine after practice.

Coughlin and Beckham did not specify exactly what happened to cause the soreness, but the coach claimed the receiver didn’t cause significant damage to the troublesome hamstring, which has kept him out of every preseason game.

“No, I don’t think Beckham hurt himself,” Coughlin said after Tuesday’s practice. “I didn’t even realize it because one of the last plays of practice [Monday] he caught a pass and ran down the sideline and looked pretty darn good. He evidently was sore [Tuesday] morning. They don’t feel like it’s a re-injury, but they’re going to continue to be cautious, if that’s what it takes. They’re saying no setback. That’s where we are on it.

“What contributed to it, I really don’t know.”

The latest setback, er, issue with the 12th overall pick only further enhances the possibility he may not be ready for the Giants’ season opener at Detroit on Sept. 8. Beckham had eyed a return on Friday, and now will have only one more opportunity to appear in the preseason – Aug. 28 against New England. Beckham also was limited during the team’s spring activities because of the hamstring.

Last week, the LSU standout boasted the Giants offense could be “one of the best in the league,” but the preseason has done nothing more than raise questions about whether the team is capable of carrying out new offensive coordinator Ben McAdoo’s new offense.

How much of a difference can Beckham make? No one knows. And no one knows when we’ll know.

“Hopefully, he gets out on the field soon because we need him,” wide receiver Marcus Harris said. “He is our first-round draft pick.”

Though Beckham is behind on the field, Coughlin said the rookie is up to speed otherwise, displaying little concern that he would have trouble acclimating to the offense when he returns to action. Keeping up with the attack after missing so much time is another matter.

“He’s been in every meeting,” Coughlin said. “He knows the offense, he knows the terminology. The stamina, the endurance part of it, those kind of things, it’s all going to have to be accomplished.”